Fitness Disclaimer: The information contained in this site is for educational purposes only. Vigorous high-intensity exercise is not safe or suitable for everyone. You should consult a physician before beginning a new diet or exercise program and discontinue exercise immediately and consult your physician if you experience pain, dizziness, or discomfort. The results, if any, from the exercises may vary from person-to-person. Engaging in any exercise or fitness program involves the risk of injury. Mercola.com or our panel of fitness experts shall not be liable for any claims for injuries or damages resulting from or connected with the use of this site. Specific questions about your fitness condition cannot be answered without first establishing a trainer-client relationship.

Phil Campbell has been phenomenally instrumental in helping me to better understand, and practically apply the principles of high intensity exercise training. In this interview we discuss the details of how this occurred, and how you can reap similar results by implementing his expert advice.

Dr. Mercola's Comments:

I first met Phil Campbell earlier this year at a fitness camp in Cancun, Mexico, and he was truly the highlight of my experience there. He's the author of the book Ready Set Go, which details how the exercises for super-fast muscle fibers can increase growth hormone, which we also discuss in depth during this interview.

He's a true veteran in the field of fitness with over 35 years experience in training professional athletes. Over the years Phil has worked with 18,000 athletes, teaching them how to run faster with the proper speed technique. He's also the associate athletic director of Bethel University in Tennessee.

He taught me how to apply the revised form of exercise we discuss and demonstrate in the video above, which has helped transform my physique and physical health.

I have previously written about this technique, which is termed Sprint 8. In this video you'll hear it first-hand from the person who designed and developed it. Hopefully, Phil will inspire you to implement this fitness strategy and transform your health as well.

There's a load of information in this interview that cannot be covered in this summary, so please, I urge you to watch the video in its entirety, or read through the transcript to get the full story.

My Path Toward Optimal Fitness

One of the first books I read on exercise, which set me on the path toward a career in health, was Dr. Ken Cooper's book Aerobics. That was back in 1968. Cooper was a physician and an Air Force Colonel, and he helped develop a fitness program for the astronauts. His program was based on cardiovascular exercise, and the book incited a revolutionary shift in how people approached exercise and fitness.

Dr. Cooper actually created the term Aerobics and I bought his program hook, line, and sinker, and it had a major impact on my life. I was incredibly cardiovascularly fit. I chose distance running as my approach, and I spent the next 40 years running.

Then, about five years ago Dr. Al Sears opened my mind to the possibility that extensive cardiovascular aerobic-type training might be counterproductive. His program introduced me to the concept that high intensity, burst-type sprints could be a far healthier alternative to long distance running. However his program is a bit more generalized.

One of the questions that stood out to me though was when you compare the two types of physiques, which would you rather have – the physique of a sprinter or a long distance runner?

Who looks healthier?

Clearly the sprinter, which was why after four decades of running, I reached a plateau and quit long distance running entirely in 2009.

Then, I met Phil Campbell… and I finally understood the connection to growth hormone and how to actually integrate the program.. Phil taught the Sprint 8 program in a specific, understandable way, and provided the physiological and scientific underpinnings of the health impact of growth hormones in somatopause.

I was hooked, and the results are unmistakable. I've been doing what is called Sprint 8 ever since, two or three times a week now since April of 2010.

What makes it work so well?

It works because it promotes human growth hormone (HGH), which is a synergistic, foundational biochemical underpinning that makes your strength training and everything else work like a charm, and effectively burns off calories.

So far I've lost 13 pounds of fat and gained over 10 pounds of muscle.

The Key Ingredient for Speed, Endurance, and Cardiovascular Health

Perhaps the most important aspect of fitness is fast and super-fast muscle fiber development. While many people focus on endurance, Phil explains that endurance comes as a by-product of super fast-twitch fiber development, which takes about a month to build.

When you work your heart anaerobically and aerobically, you get great endurance.

However, endurance comes and goes in as little as two weeks. According to Phil, you can double your endurance in just two weeks, but you can also lose it pretty quickly.

The beauty of Sprint 8 exercises is that you don't have to worry about the regular, traditional cardio exercises because you're going to get that (and more) anyway through this program. In fact, Sprint 8 type exercises can dramatically improve your cardiovascular fitness and fat-burning capabilities in a fraction of the time.

But First, Know Your Muscle Fibers…

We now know, from more recent research, that you have three muscle fiber types with three energy systems that fit together. The three different types of muscle fibers are:

Slow (red muscle, which contains more oxygen)

Fast (white muscle)

Super-fast (white muscle)

Phil further explains:

"… [T]he blood supply is going to the red muscle. The white muscle really doesn't get a lot of blood because it doesn't need a lot of blood. It gets its energy from the stored up energy in your body. That's six to eight seconds worth of stored up energy and through the oxygen you breathe for 30 seconds or less.

The white fiber essentially has two types of fiber -- what the researchers call 2A and 2B -- but it's easier to call it fast twitch and super-fast fiber.

The fast twitch fiber moves about five times faster than the slow, but about 30 percent of your muscle fiber, the super-fast fiber, move 10 times faster than the slow.

Working your super-fast fiber forces your heart to work anaerobically. So you get a great comprehensive heart muscle workout when you do that."

If you don't work all three muscle fiber types and energy systems, then you're not going to work both processes of your heart muscle. Many mistakenly believe that cardio works out your heart muscle, but what you're really working is your slow twitch muscle fibers. You're not working the anaerobic process of your heart.

Your heart actually has two totally different processes; the aerobic process and the anaerobic process.

The anaerobic process lines up with your fast andsuper-fast twitch muscle fibers that are used during Sprint 8 type exercises.

This is why you may not see results even though you spend an hour on the treadmill a few times a week – you're basically denying the natural physiology of your body by not working the other half of your muscle fibers; your fast-twitch muscles.

In addition, about half of your muscle fibers are fast twitch fibers, and if you do not exercise these fast muscles, they begin to atrophy, which is detrimental to physical health and fitness.

"A new study shows, and this is really exciting, that when you work the fast twitch fiber and work your heart muscle anaerobically, your body releases exercise-induced growth hormones (HGH) that actually mimic taking injections of growth hormones.

… [Y]ou get as much as a 530 percent increase in growth hormone!

… It stays your body for two hours, going after body fat like a heat seeking missile. It's so powerful that if you were to do the program today and monitor your blood, it will look like you injected growth hormone illegally. That's why there is no HGH test for Olympic athletes today."

THIS is why Sprint 8 type exercises can revolutionize your health and fitness!

It's important to realize that your body does not produce HGH after long, slow exercise. Only Sprint 8-style exercises -- the short, quick-burst anaerobic type of exercise, for short periods of time -- accomplish this.

Another benefit is that the Sprint 8 protocol takes just 20 minutes, three times a week, and then you're done!

The research is so clear about the superior benefits of this type of exercise that the American Heart Association and the American College of Sports Medicine have now totally changed their exercise cardio guidelines, according to Phil.

Long, slow cardio simply doesn't work because it does not work both processes of your heart; it doesn't work all three muscle fiber types, nor your three energy systems.

Their new guidelines now state that you can do moderate intensity cardio, five days a weeks for 30 minutes, or you can do vigorous intensity cardio for 20 minutes, three days a week, which is exactly what Sprint 8 is.

It's really an issue of fast recovery versus growth hormone release. Which one are you aiming for?

In order to promote HGH release, you do need to restrict sugar intake post-exercise, while carbs can benefit those more interested in fast recovery, such as professional athletes.

To explain and expound on this issue further, Phil provided the following details:

"When I train young athletes in speed – www.40speed.com - I explain to them that the research shows 20 to 25 grams of protein (within 30 minutes of training) with a 4 to 1 ratio of carbs to protein, starts the recovery process quicker.

This advice is given to everyone as general advice in most fitness magazines today and is mostly based on research led by Dr John Ivey on young cyclists who have to perform several days in a row, and a quick recovery during competition is extremely important. Clearly, young athletes more concerned with fast recovery than maximizing HGH release should use this strategy.

However, if you are middle-aged, or in a non-competitive phase of training, and keeping HGH circulating as long as possible is your goal, then protein intake (20 to 25 grams after training) is a great strategy, but you need to monitor the glycemic impact of carbs because of the variable impact of carbs on insulin, which in turn impacts the HGH release process.

There are a couple of variables that come into play that can change the rules for adults wanting to maximize human growth hormone from exercise.

Research shows that a spike of insulin after training increases somatostatin (the hormone that shuts down HGH).

So, here's where this issue gets complicated, because it's difficult to estimate the glycemic impact of food on different people with different muscle to body fat ratios. And what makes this issue very complicated is that the insulin producing process is variable for every adult to some degree.

It depends on where you are on the Metabolic Syndrome scale. Metabolic Syndrome just became an official medical condition in 2001, and the research shows that even a few carbs can spike insulin for some people with insulin resistance.

If you are lean and do not need to drop a lot of body fat, then you can probably eat some carbs without spiking insulin -- and maybe even some refined sugar depending on the interaction of the carbs with an intake of post-training protein, which will somewhat negate the impact of the carbs on the insulin response – as opposed to an intake of carbs on an empty stomach.

So, as you can see, there are many variables that come into play.

In short, carbs with the protein can be good after training as long as the glycemic response doesn't spike your insulin.

Research shows that the insulin response of an individual is lessened with youth and/or lean body weight (muscle vs. body fat), and that's another reason why it's so important to maintain muscle throughout life.

From a performance training strategy perspective for runners, I would suggest consider training with the strategy of maximizing HGH release (except on really hot days or on the one-long-run-a-week day) because this strategy should build muscle to make you faster, and reduce body fat so you have less to carry.

For competitions, and those hot, long-training days, I'd suggest using the quick recovery strategy of 1 to 4 ratio of protein to carbs, because in this instance, your body does not care what the quality of glucose is; it just needs glucose."

Special Note about Fructose

The following point is a minor one, but it's significant nonetheless.

Keep in mind that the glycemic index of carbs has become slightly outdated due to the more recent research on fructose.

Fructose actually causes a very minor, if any, change in insulin response, but we know it's incredible damaging. It causes this damage through other mechanisms besides insulin.

Therefore, I now look at carbohydrates as the percentage of fructose it contains. And higher dextrose, although it can raise insulin, may not cause as many adverse biochemical side effects as fructose does…

What You Need to Know about Somatopause, and Why Sprint 8 is so Beneficial

The concept of somatopause is frequently overlooked, but it is what makes growth hormone production so important, and why Sprint 8 exercises are so incredibly beneficial.

Somatopause is tied directly to decreased amounts of growth hormone (HGH), which is also called "the fitness hormone."

As you reach your 30s and beyond, your levels of HGH begin to drop off quite dramatically, which triggers somatopause. This is part of what drives your aging process. You start putting on body fat and losing muscle; you become more fatigued, and the "middle age spread" sets in.

It has been my experience that nearly everyone over 30 has dramatically abnormally low levels of this important hormone because they begin leading increasingly sedentary life styles.

Children and most animals in the wild do not run marathons or lift weights, they move at high speeds for very short periods of time and then rest. This is natural and what optimizes the production of growth hormone.

The higher your levels of growth hormone, the healthier and stronger you're going to be. And the longer you can keep your body producing higher levels of HGH, the longer you will experience robust health and strength.

I totally agree with Phil when he says:

"Really, if you think about it, when you're looking at exercise-induced growth hormone it's like you're listening to your body tell you how, as a human being, you should exercise. Because when you do it this way, your body releases this huge amount of growth hormone that does so many things synergistically for you for two hours after you work out."

How to Perform Sprint 8 Exercises

Here's a summary of what a typical Peak Fitness routine might look like using a recumbent bike (although you can perform this on an elliptical machine or treadmill, or with any type of exercise you prefer):

Warm up for three minutes

Exercise as hard and fast as you can for 30 seconds. You should feel like you couldn't possibly go on another few seconds

Recover for 90 seconds

Repeat the high intensity exercise and recovery 7 more times

Be mindful of your current fitness level and don't overdo it when you first start out.

If you are not in great shape and just starting this you may want to start with just two or three repetitions, and work your way up to eight. You may need to start with just walking and when you do your 30 second bursts your legs would be moving as fast as possible without running - and your arms would be pumping hard and fast.

Ultimately you want to exercise vigorously enough so you reach your anaerobic threshold as this is where growth hormone release is triggered.

Whatever activity you choose, by the end of your 30 second sprint period you will want to reach these markers:

It will be relatively hard to breathe and talk because you are in oxygen debt

You will start to sweat profusely. Typically this occurs in the second or third repetition unless you have a thyroid issue and don't sweat much normally.

Your body temperature will rise

Lactic acid increases and you will feel a muscle "burn"

If you are using cardio equipment like an elliptical or bike, you don't need to reach any "magical" speed. It's highly individual, based on your current level of fitness. But you know you're doing it right when you're exerting yourself to the point of typically gasping for breath, after a short burst of activity.

Do this exercise two to three times a week, and you're virtually guaranteed to drastically improve your HGH production.

Special Warning to Over-Achievers…

I want to stress this point: perform Sprint 8 only two to three times a week. I'm continuously shocked and surprised when people say they do this program every day!

Folks, if you do that your body will shut down. You'll be bedridden. Nearly every time someone tells me they are doing it more than four times a week, they are not doing it properly as they are not pushing themselves hard enough and getting their heart rate up to their maximum.

Phil explains:

"You just can't [do that]. I've tried to experiment with the program in as many ways as possible to learn more about it.

I can do it four days straight but it's virtually impossible. My brain just shuts down. I'm totally lethargic the next day. That's really too much… I've never ever been able to do it five days in a row."

So please understand that not only do you not NEED to do it more than three times a week, you may actually cause more harm than good if you over-do it.

To get all the benefits from Sprint 8, just focus on gradually increasing intensity, as opposed to doing it more frequently.

Again, this interview contains countless additional nuggets of pure gold, so please listen to it in its entirety, or read through the transcript at your leisure. It very well could change your life. I know it has had the most dramatic impact on my body and health than any other fitness program I've ever tried.

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FITNESS DISCLAIMER: The information contained in this site is for educational purposes only. Vigorous high-intensity exercise is not safe or suitable for everyone. You should consult a physician before beginning a new diet or exercise program and discontinue exercise immediately and consult your physician if you experience pain, dizziness, or discomfort. The results, if any, from the exercises may vary from person-to-person. Engaging in any exercise or fitness program involves the risk of injury. Mercola.com or our panel of fitness experts shall not be liable for any claims for injuries or damages resulting from or connected with the use of this site. Specific questions about your fitness condition cannot be answered without first establishing a trainer-client relationship.